The Arab satellite television channel al-Jazeera is to pull its reporters out of Iraq after one of them was killed during a US air raid on Baghdad.

"I cannot guarantee anyone's safety," the news editor, Ibrahim Hillal, told reporters. "We still have four reporters in Baghdad, we will pull them out. We have one embedded with US forces in Nassiriya; we want to pull him out."

The move followed a day in which three journalists were killed by US fire in separate attacks in Baghdad, leading to accusations that US forces were targeting the news media.

Reuters cameraman Taras Protsyuk, 35, was killed when an American tank fired a shell directly at the Reuters suite on the 15th floor at the Palestine hotel, where many journalists are staying.

Jose Couso, 37, a cameraman for the Spanish television channel Tele 5, was wounded in the same attack and died later in hospital. Samia Nakhoul, the Gulf bureau chief of Reuters, was also injured, along with a British technician, Paul Pasquale, and an Iraqi photographer, Faleh Kheiber.

Earlier, al-Jazeera cameraman Tarek Ayyoub, a 35-year-old Palestinian who lived in Jordan, was killed when two bombs dropped during a US air raid hit the satellite station's office in the Iraqi capital.

American forces also opened fire on the offices of Abu Dhabi television, whose identity is spelled out in large blue letters on the roof.

All the journalists were killed and injured in daylight at locations known to the Pentagon as media sites. The tank shell that hit the Palestine hotel slammed into the 18-storey building at noon, shaking the tower and spewing rubble and dirt into hotel rooms at least six floors below.

The attack brought pandemonium in the hotel which lies on the east side of the Tigris. It was adopted by all remaining western journalists in the city after advice from the Pentagon to evacuate from the western side of the river.

Central command in Qatar said its troops had been responding in self-defence to enemy fire but witnesses dismissed that claim as false. According to a central command statement, "commanders on the ground reported that coalition forces received significant enemy fire from the hotel and consistent with the inherent right of self-defence, coalition forces returned fire".

The statement added: "Sadly a Reuters and Tele 5 journalist were killed in this exchange. These tragic incidents appear to be the latest example of the Iraqi regime's continued strategy of using civilian facilities for military purposes."

But journalists in the hotel insisted there had been no Iraqi fire.

Sky's correspondent, David Chater, said: "I never heard a single shot coming from the area around here, certainly not from the hotel," he said.

BBC correspondent Rageh Omaar added that none of the other journalists in the hotel had heard any sniper fire.

Chater said he saw a US tank pointing its gun at the hotel and turned away just before the blast. "I noticed one of the tanks had its barrel pointed up at the building. We went inside and there was an almighty crash. That tank shell, if it was an American tank shell, was aimed directly at this hotel and directly at journalists. This wasn't an accident. It seems to be a very accurate shot."

Geert Linnebank, Reuters editor-in-chief, said the incident "raises questions about the judgment of the advancing US troops who have known all along that this hotel is the main base for almost all foreign journalists in Baghdad".

Journalists, a watchdog group that defends press freedoms, demanded an invesigation in a letter to the US defence secretary, Donald Rumsfeld. "We believe these attacks violate the Geneva conventions," the letter said, adding that even if US forces had been fired on from the Palestine hotel "the evidence suggests that the response of US forces was disproportionate and therefore violated humanitarian law".

During the Afghan war, two supposedly smart US bombs hit the Reuters office in Kabul and many suspect the attack was no accident. It happened at a strategic moment, two hours before the Northern Alliance took over the city.

US military officials at central command said they were investigating and added that the casualties were "regrettable". "We know that we don't target journalists," said Brigadier General Vince Brooks, deputy director of operations.

Al-Jazeera correspondent Tarek Ayyoub was broadcasting live to the satellite station's 7am news bulletin when US aircraft fired two missiles at the bureau building, killing him and injuring a colleague. Two Iraqi staff are missing.

Ibrahim Hilal, al-Jazeera's chief editor at its headquarters in Qatar, said a US warplane was seen above the building before the attack. "Witnesses saw the plane fly over twice before dropping the bombs. Our office is in a residential area and even the Pentagon knows its location," he said.

Al-Jazeera correspondent Majed Abdul-Hadi said the bombardment was probably deliberate.

In Doha last night al-Jazeera's chairman, Hamad bin Thamer, said the channel "could not ascertain" if its Baghdad bureau had been targeted by the US. But he dismissed American claims that there had been gunfire coming from the building at the time of the attack.

"This was absolutely and categorically denied by other reporters and our reporters present on the ground," he said.

Mr Ayyoub, 35, a Palestinian born in Kuwait, had not intended to go to Baghdad but as the war dragged on he felt he had to work there, and al-Jazeera agreed to let him work in Baghdad.

His widow, Dima Ayyoub, launched a vitriolic attack on America: "My message to you is that hatred breeds hatred," she said in a live telephone link-up from her home in Amman, Jordan. "I cannot see where is the cleanness in this war. All I see is blood, destruction and shattered hearts. The US said it was a war against terrorism. Who is committing terrorism now?"